Build fails

[bparanj]

I have downloaded this repo to the folder: ~/Documents/diamol-master. When running the first build I get the error:

Started by user diamol
Checking out git http://gogs:3000/diamol/diamol.git into /data/workspace/diamol@script to read ch11/exercises/Jenkinsfile
The recommended git tool is: NONE
No credentials specified
 > git rev-parse --resolve-git-dir /data/workspace/diamol@script/.git # timeout=10
Fetching changes from the remote Git repository
 > git config remote.origin.url http://gogs:3000/diamol/diamol.git # timeout=10
Fetching upstream changes from http://gogs:3000/diamol/diamol.git
 > git --version # timeout=10
 > git --version # 'git version 2.26.2'
 > git fetch --tags --force --progress -- http://gogs:3000/diamol/diamol.git +refs/heads/*:refs/remotes/origin/* # timeout=10
 > git rev-parse refs/remotes/origin/master^{commit} # timeout=10
 > git rev-parse origin/master^{commit} # timeout=10
ERROR: Couldn't find any revision to build. Verify the repository and branch configuration for this job.
ERROR: Maximum checkout retry attempts reached, aborting
Finished: FAILURE

Any ideas on how to fix this issue? I am on Ubuntu 20.04.